Paper-making machinery



NOV. 19, 1968 MEANS 3,411,985

PAPERMAKING MACHINERY Filed March 9, 1965 4 Sheets-Sheet 1 H Hi,

RECIRCULATION OVERFLOW AIR 1 :cusmon AIR I NVENTOR. JOHN A. MEANS WFI,MRAQMZ his A TTORNEYS NOV. 19, 1968 J MEANS 3,411,985

PAPER-MAKING MACHINERY Filed March 9, 1965 4 Sheets-Sheet 2 SPOOLSCROSS- MACHINE DlSTRIBUTOR cnoss- MACHINE DISTRIBUTOR AIR 92 CUSH'ONRECIRCULATION FIG 7 OVERFLOW HALF I 94 SPOOLS B6 RECIRCULATION OVERFLOWHALF P 86 s OOLS f L l I.

FIG. 8 g: 84 I INVENTOR. :I= JOHN A. MEANS hlS ATTORNEYS J. A. MEANSNov. 19, 1968 PAPER-MAKING MACHINERY 4 Sheets-Sheet 3 Filed March 9,1965 INVENTOR. JOHN A. MEANS BY J F GM IM- his ATTORNEYS Nov. 19, 1968J. A. MEANS 3,411,985

PAPER-MAKING MACHINERY Filed March 3*, 1965 4 Sheets$heet 4 FIG. /2

INVENTOR.

JOHN A. MEANS his A TTORNEYS United States Patent 3,411,985 PAPER-MAKINGMACHINERY John A. Means, South Norwalk, Conn., assignor to TimeIncorporated, New York, N.Y., a corporation of New York Filed Mar. 9,1965, Ser. No. 438,194 6 Claims. (Cl. 162212) ABSTRACT OF THE DISCLOSUREA paper-stock-flow system in which paper stock flows first through afiat channel and then through a plurality of parallel pipes incommunication with the flat channel at the downstream end thereof isprovided with spoolshaped deflocculation means in the flat channel andwith rounded entrances to the pipes. The rounded entrances are shaped asportions of spools. A recirculation overflow is provided in the flowsystem for withdrawing the fastestmoving portion of the stock from thefiow system so that the standard deviation of the speed of the portionof the stock remaining in the flow system for delivery to the Wet end ofa paper machine is reduced.

This invention relates to paper-making machinery and, more particularly,to a novel and highly-effective papermaking-machine fiow systemproviding a stock flow of maximum homogeneity and uniformity of velocityat the slice and minimum tendency to hang up.

A never-ending quest of paper manufacturers is for a stock-flow systemproviding at the slice of a paper-making machine a fiow of deflocculatedor homogeneous paper stock which is of uniform velocity from one side ofthe slice to the other. Another quest, no less urgent, is for a fiowsystem adapted to accept a wide variety of paper stocks without givingrise to hang-up of the stock.

Numerous improvements facilitating these ends have been made, butpresent-day machines are still deficient in that parts of the paperstock emanating from the slice have a velocity, even in the case of themost advanced machines, substantially exceeding that of other parts ofthe stock. It is particularly the fastest-moving to 30% or so of thestock emanating from the slice which is objectionable from thestandpoint of producing detectable imperfections in the resulting web ofpaper. Similarly, attempts to deflocculate stock without promotinghang-up thereof have met with limited success, because these attemptsare to some extent incompatible with attempts to deliver paper stock tothe slice a uniform velocity from one side of the slice to the other.

An object of the present invention is to overcome the deficiencies ofconventional paper-making machines pointed out above.

In particular, an object of the invention is to produce apaper-stock-fiow system adapted to produce at the slice of apaper-making machine a flow of stock having a virtually uniform velocityfrom one side of the slice to the other. Another object of the inventionis to produce a paper-stock-fiow system which is adapted to deflocculatestock and guide the fiow thereof and which has a minimum tendency topromote hang-up.

Certain objects of the invention are accomplished by providing, in apaper-stock-fiow system for delivering a paper stock to a paper-formingmachine, means for establishing a flow of paper stock in the system,various parts of the stock at a given location in the system moving atdifferent speeds, and stock-withdrawal means at that location forWithdrawing from the flow a portion of the stock to reduce the standarddeviation of the speeds of the parts of the stock remaining in the flowsystem and to permit independent adjustments of the rate of deliver ofstock Patented Nov. 19, 1968 to the fiow system and the rate of deliveryof stock by the flow system to the paper-forming machine.

Other objects of the invention are accomplished by the provision of adeflocculation chamber having first and second opposed walls generallyparallel to each other and separated from each other a distance a andstock deflocculation means mounted between and connected to the walls,the stock deflocculation means having an axis of length a normal to thewalls and extending therebetween and a peripheral surface of revolutiongenerated by a semicircle. The semicircle has a center a distance x fromthe first wall and R from the axis and is a line of partial revolutiongenerated by a point. The point is located a distance r from the centerand revolved about the center through an arc of The are lies between theaxis and a limiting diametric chord of the semicircle parallel to theaxis and is in the plane of the chord and axis. The semicircle describedabove generates the peripheral surface of the stock-deflocculation meansby revolution about the axis.

An understanding of other aspects of the invention may be gained from aconsideration of the following detailed description of severalrepresentative embodiments thereof, taken in conjunction with theaccompanying figures of the drawings, in which:

FIG. 1 is a sectional schematic side elevation of a portion of aconventional paper-stock-fiow system;

FIG. 2 is a sectional schematic side elevation of a portion of a firstrepresentative embodiment of a paper-stockfiow system constructed inaccordance with the present invention;

FIG. 3 is a sectional schematic side elevation of a portion of a secondrepresentative embodiment of apparatus constructed in accordance withthe invention;

FIG. 4 is a sectional schematic side elevation of a portion of a thirdrepresentative embodiment of apparatus constructed in accordance withthe invention;

FIG. 5 is a sectional schematic side elevation of a first modificationof a lower part of the structure of FIG. 4;

FIG. 6 is a sectional schematic side elevation of a second modificationof a lower part of the structure of FIG. 4;

FIG. 7 is a sectional schematic side elevation of a first modificationof the upper part of the structure of FIG. 4;

FIG. 8 is a sectional schematic side elevation of a second modificationof the upper part of the structure of FIG. 4;

FIG. 9 is a sectional schematic side elevation of a portion of anotherrepresentative embodiment of apparatus constructed in accordance withthe invention;

FIG 9A is a view substantially along the line 9A9A of FIG. 9 and lookingin the direction of the arrows;

FIG. 10 is a view substantially along the line 1010 of FIG. 4 andlooking in the direction of the arrows;

FIG. 11 is a View taken substantially along the line 11-11 of FIG. 10and looking in the direction of the arrows;

FIG. 12 is a detailed plan view of a portion of apparatus shown, forexample, in FIG. 3;

FIG. 13 is a view substantially along the discontinuous line 13-13 ofFIG. 12 and looking in the direction of the arrows; and

FIG. 14 is a view substantially along the discontinuous line 14-14 ofFIG. 13 and looking in the direction of the arrows.

FIG. 1 shows a portion of a conventional flow system designatedgenerally by the numeral 20. The flow system 20 includes a conduit 22for carrying a paper stock. The conduit 22 communicates with anexplosion chamber 24 adapted to defiocculate the stock by causing it toimpinge on a fiat surface 26, to acquire random agitated movement ofvarious parts thereof, and abruptly to change its overall direction ofmovement. The stock passes from the explosion chamber 24 through achannel 28 and a channel 30 forming an angle with the channel 28 andthrough a first distributing or rectifying roll 32. The distributingroll 32 is a cylindrical member provided with performations 34 in itsperiphery and adapted to be rotated about its axis at a speed of to 30rpm. to assist in deflocculation of the stock. The stock then forms alayer or pond 36 within which are mounted a pair of distributing rolls38, 40 similar to the distributing roll 36 for the purpose of furtherassisting the defiocculation of the stock. A chamber 42 above the pond36 provides a pressure dome 44 within which compressed air is maintainedfor the purpose of controlling the flow rate of the stock through aslice 46.

The structure described above provides imperfectly for stockdeflocculation. The requirement that all of the stock passing throughthe flow system also pass through the slice 46 establishes the flow ratethrough the flow system 20 as a function of the rate at which stockemanates from the slice 46. Thus, a reduction in the latter ratenecessitates a corresponding reduction in the former with the resultthat the velocity necessary to facilitate complete deflocculation of thestock by the distributing rolls 32, 38, and 40 and to preventrefiocculation may not be maintained.

The structure described above also provides imperfectly for uniformstock velocity at the slice 46. The fastest 10% to or so of the stockemanating from the slice 46 is the most objectionable from thestandpoint of producing unevenness in the fiow rate of the stock acrossthe slice from one side to the other.

FIG. 2 shows a first embodiment of apparatus constructed in accordancewith the invention. The apparatus improves the conventional apparatus ofFIG. 1 by eliminating, as by recirculation, a variable proportion of thestock from the flow system so that the stock-flow rate past thedistributing rolls 32 and 38 is not a unique function of the rate atwhich stock is discharged from the slice. Parts of the apparatus of FIG.2 are identical to corresponding parts of FIG. 1 and bear the samereference numerals. In FIG. 2, however, the distributing roll has beenremoved and replaced by a sloping partition plate 50 having its upstreamend 52 raised with respect to the slice 46 and located at an elevationapproximately equal to that of the highest point of the distributingroll 38. A vertical panel 54 in the chamber 42 is connected influid-tight relation to the sloping partition 50, and an adjustablestock drain 56 is provided at the junction of the panels 50 and 54 toremove a variable proportion of the stock from the main stock-flowstream. The drain 56 is maintained covered by stock, so that thepressure dome or air cushion 44 is sealed. The drain 56 has suflicientcapacity to remove all the stock spilling over the upper edge 52 of thepartition plate 50, regardless of the speed of operation of the machinewithin its intended limits. Thus, the system is adapted to operate inequilibrium, the level of the Water in the pond 36 being, for example,that shown in FIG. 2.

The upper edge 52 of the partition plate 50 is so disposed thatsubstantially all of the stock not passing through the distributing roll38 is removed from the main stock-flow stream. Preferably, the drain 56returns the removed stock to the source of stock for recirculation.

The flow system 20" of FIG. 3 is similar to the apparatus of FIG. 2except that portions of the apparatus of FIG. 2 rendered unnecessary bythe modified design have been eliminated. Thus, the chamber 42 have beenreconstituted as the chamber 42, the vertical walls 54 and 60 (FIG. 2)have been merged into a single sloping wall 62, and the vertical Wall 61has been replaced by a wall 63 sloping upwardly toward the sloping wall62. Also, the anguar junction 65 has been replaced by a rounded junction67, the channel 30 diverging markedly from the junction 67 to thedistributing roll 32.

FIG. 4 shows another embodiment of the invention, in which across-machine distributor 64 is employed. The distributor 64 feeds thestock through a flat channel 66 and a generally prismatic chamber 68 inwhich is mounted a rotatable rectifier roll 70. The outer wall 72 of thechamber 68 is cylindrically curved about the axis of the rectifier roll70. A small space 76 between the outer circumference of the rectifierroll and the inner'circumference of the rounded wall 72 is of suificientsize to prevent stock hangup but small enough to ensure thatsubstantially all of the flow is through rather than around the roll 70. The rectifier roll 70 is provided with apertures 78 to facilitate thedefiocculation of the stock and the rectification of stock flow. Thewall 80 of the chamber 68 opposite the cylindricallycurved wall 72 isgenerally fiat and, in a flow system in which stock flow is changed froma horizontal direction in the section 66 to a vertical direction in thesection 82, lies in a plane forming an angle of about 45 to thehorizontal. A small space 77, similar in function and operation to thespace 76, is left between the outer circumference of the rectifier roll70 and the wall 80. Stock passes principally through the interior of theroll 70, the function and operation of the roll 70 being similar tothose of the rolls 32, 38, and 40.

The vertical section 82 is provided with structure which for conveniencemay be referred to as a row of full spools 84. As described in detailhereinafter, the full spools 84 facilitate the deflocculation of thestock without contributing to stock hang-up.

A chamber 86 is connected by a short passage 88 with the verticalsection 82. The fastest moving 10% to 30% or so of stock rising throughthe section 82 passes through the passage 88 and spills into a pond 90within the chamber 86. An adjustable overflow drain 93 is provided atthe bottom of the pond 90 to remove the accumulated stock and return itto the stock source for recirculation. The chamber 86 contains an airpressure dome 92 providing an air cushion to absorb surges in the stockflow and to maintain a head of pressure upon the stock in a channel 94extending horizontally from the junction of the channels 82 and 88toward the slice 96.

As a close approximation, the fastest moving 10% to 30% of the stock isremoved from the main stockflow stream when a corresponding percentageby volume of the stock is withdrawn through the drain 93. That isbecause the portions of the stock having the highest velocities tend tocontinue in a straight line into the recirculation overflow, while theportions of the stock having lower and more nearly uniform velocitiesare amenable to diversion through a substantially ninety-degree bend.Thus segre gated, the portions of the stock having lower and more nearlyuniform velocities are directed to the slice 96.

The fragmentary structure shown in FIG. 5 is identical to that of FIG. 4except that the chamber 68 is removed, and a channel 66 similar to butlonger than the channel 66 curves through a section 98 directly into thevertical channel 82 similar to but longer than the channel 82 shown inFIG. 4. The rectifier roll 70 is thus eliminated in the structure ofFIG. 5.

The structure of FIG. 6 is even simpler than the structure of FIG. 5. Inthe embodiment of'FIG. 6, the crossmachine distributor 64' is similar tothe cross-machine distributor 64 shown in FIGS. 4 and 5 but ejects thestock upwardly through a channel 82". The horizontal channel 66 and thecurved section 98 shown in FIG. 5 are eliminated in the embodiment ofFIG. 6.

The embodiment of FIG. 7 is similar to that of FIG. 4 except that theupper portion of the embodiment of FIG. 7 is modified to include a rowof what for convenience may be referred to as half spools 100 mounted inthe horizontally-extending channel 94'. The half spools 100 aredescribed in detail. hereinafter. Briefly, their function is to convertthe flow from a wide flat stream in the channel 94 to flow through aplurality of tubes (only one of which, a tube 102, is shown in FIG. 7)without promoting hangup of the stock and without giving rise tounwanted variations of stock velocity across the slice.

The embodiment of FIG. 8 is identical to that of FIG. 7 but discloses aduck-bill tube 104 connected to a flat section 106 which in turncommunicates with a tapering slice 108. The duck-bill tube 104, atransition piece of circular cross section at its upstream end orentrance and of rectangular cross section at its downstream end or exit,is narrower in the plane of FIG. 8 at its downstream end than at itsupstream end. In plan view, however, the tube 104 is wider at itsdownstream end than at its upstream end. Compare, for example, FIGS. 9and 9A.

The embodiment of FIG. 9 is similar to that of FIG. 2 but eliminates thesecond rectifier roll 38 and includes a flat section 112 and half spools114 mounted at the downstream and of the fiat section 112 in atransition area between the flat section 112 and tubes 116. The tubes116 include a comically-divergent portion 117 which provides increasingcross-sectional flow area for the stock passing therethrough. Theconically-divergent portion 117 communicates with a duck-bill tube 118which is narrower in the plane of FIG. 9 at its downstream end than atits upstream end. In the plane of FIG. 9A, the tube 118 is wider at itsdownstream end than at its upstream end. Thus, the tapering tube 117causes deceleration of the stock flowing therethrough, and the tube 118converts the shape of the cross-sectional flow area from circular at theupstream end of the tube 118 to rectangular at the downstream end of thetube 118. The tube 118 is connected to a flat section 119 in which stockflowing from the various tubes 118 is united into a single stream andquieted. The flat section 119 in turn communicates with a slice.

The embodiment of FIG. 9further differs from that of FIG. 2 in having astock-acceleration plate 120 and an impingement surface 120'. Thestock-acceleration plate 120 curves above a substantial portion of thecircumference of the roll 32 in closely-spaced-apart relation thereto toprovide a restricted stock-flow channel 121 immediately adjacent to anddownstream of the roll 32. The impingement surface 120 is so locatedwith respect to the flow of stock through the channel 121 that the stockimpinges on the surface 120. This impingement serves three purposes.First, it dissipates some of the energy in the stock, thereby tending toslow some of the fastest moving parts thereof. Second, it facilitatesdiversion of a portion of the stock flow into the recirculationoverflow, with advantageous results set forth above. Third, itfacilitates defiocculation of the stock. It should be noted, inconnection With this last point, that the distributing roll 32, thoughintended to facilitate deflocculation, to some extent facilitatesflocculation. That is because the relatively large cross-sectional flowarea which must prevail in the vicinity of the distributing roll 32 is aregion Where stock moves relatively slowly. Further, the distributingroll 32 (or any other distributing roll) may generate lumps because ofits rotation. In particular, stock fibers which collect on a surface ofthe roll 32 when the roll is in a given orientation may break free as aconglomerate mass when the roll rotates through 180.

The stock-acceleration plate 120 and impingement surface 120' assurethat the stock is deflocculated, and the flat section 112 is ofsufficiently small cross-sectional flow area to assure thatreflocculation does not occur. The half spools 114, tubes 116,conically-divergent portions 117, duck-bill tubes 118, and flat section119 facilitates the establishment of a uniform stock-flow at the slicefrom one side to the other.

FIGS. 10 and 11 show the whole spools 84 in detail. The spools 84 arepreferably made of stainless steel for corrosion and hang-up resistance.The spools 84 constitute stock-defiocculation, stock-flow-obstruction,or stock-flowchanneling means 124 and are mounted between and 6connected to a first wall 122 (FIGS. 10 and 11) and a second wall 123(FIG. 10) spaced apart therefrom a distance d. The walls 122 and 123 andside walls 134 and 136 define a deflocculation chamber 127. Each spool84 has an axis of length d normal to the walls 122 and 123 and aperipheral surface 125 of revolution generated by an imaginarysemi-circle 126. The semicircle 126 has a center C a distance x from thefirst wall 122 and R from the axis A of the spool 84. The semicircle 126is in turn a line of partial revolution generated by a point P which isa distance r from the center C and which is revolved about the center Cthrough an arc of 180 extending from a point y to a point z. The arelies between the axis A and a limiting diametric chord K of thesemicircle parallel to the axis A and is in the plane of the chord K andaxis A. The semicircle thus generattd is revolved about the axis A togenerate the peripheral surface of the spool 84.

Preferably, the distance d separating the walls 122 and 123 is equal totwice the radius r of the semicircle which generates the peripheralsurface of the spool 84, though it may be somewhat less than twice theradius r. In the preferred case where the distance d is exactly twicethe radius r, the spool 84 is tangential along a circle at its end 130to the wall 122 and at its end 132 to the wall 123.

The distance between the center C of the semicircle 126 and the axis Aof the spool 84, namely the distance R, is preferably equal to orgreater than the distance r between the center C of the semicircle 126and a point P on the semicircle.

Preferably also, the distance x between the center C and the wall 122 or123 is equal to the radius r of the semicircle 126.

Thus, preferably, a pair of adjacent spools 84 define between them, in aplane through the axes of the spools, a cross-sectional flow area ofcircular section. See FIG. 11. The cross-sectional flow area throughthat plane is about 27% to 50%, and preferably 30% to 35%, of the totalcross-sectional area of the portion of the chamber in which the spools84 are mounted. Accordingly, the spools 84 occupy in that plane fromabout 73% to about 50%, and preferably 70% to 65%, of the totalcrosssectional area of the portion of the chamber in which the spools 84are mounted. In general, the smaller the ratio of flow area to totalarea in that plane, the more violent the deflocculating action producedby the spools.

Fastening means such as bolts passed through the stockxiefiocculationmeans 124 facilitate tying together opposite walls of the channel inwhich they are mounted and hence contribute to the strength of the flowsystem.

At the edges 134 and 136 of the portion of the flow system containingthe full spools 84, half spools may be mounted.

At the left end of the row of whole spools 84 shown in FIG. 10, a halfspool 138 is illustrated. The half spool 138 is identical, except asregards its orientation, to the half spools shown in FIGS. 12 and 13.From another standpoint, the half spool 138 is identical to the half ofa whole spool 84 on either side of a plane containing the axis of thewhole spool 84. The half spool 138 is mounted with its flat side 139parallel to the general direction of stock flow therepast and flushagainst the wall 134.

A whole spool 84 is illustrated at the right end of the row of spoolsshown in FIG. 10. This arrangement is preferred to the arrangementillustrated at the left end of the row of spools shown in FIG. 10,because the arr-angernent at the right end of the row of spools 84 shownin FIG. 10 eliminates the angular junction 132 between the half spool138 and the wall 134 and thus further minimizes the possibility ofhang-up. In the arrangement shown at the right end of the row of spools84 of FIG. 10, the section of the right-hand flow channel in the planeof the axes of the spools 84 is of course semicircular.

In accordance with the invention, the stock is caused to flow past thestock deflocculation means 124 at a velocity sufficient to causeturbulence in the stock on passing the 7 stock-defiocculation means.Typically, the required velocity is at least 10 feet per second. An aircushion such as the cushion 92 (FIG. 8) and a quieting channel such asthe channel 106 (FIG. 8) are employed to advantage downstream of thefull spools 84 to facilitate subsidence of the turbulence.

FIGS. 12-14 show an arrangement in which half spools 142 constitutestock-flow-channeling means arranged in a row to provide a transitionbetween a fiat flow channel 144 and a plurality of tubes 146 secured tohollow fittings 147. The semicircle 150 shown in FIG. 13 is rotated notthrough an arc of 360, as in the case of the full spools, but, rather,through an arc of 180 which is angularly limited by a planesubstantially normal to the direction of stock fiow, the arc lyingupstream of the plane.

Quarter spools 152 and 154 border the edges 156 and 158 of the flowchannel 144. The quarter spools 152 and 154 have a peripheral surface ofrevolution generated by a semicircle which is revolved about an axisthrough an arc of substantially 90, the are being angularly limited by afirst plane substantially normal to the direction of stock flow and asecond plane substantially normal to the first plane. The semicirclelies entirely upstream of the first plane.

The preferred relations between d, r, R, and x are the same for the halfand quarter spools as for the full spools.

The full spools described above facilitate the deflocculation of stock,and the partial spools facilitate the division of stock flowing in asingle wide flat channel into a plurality of separate streams. Thesefunctions are performed without promoting hang-up of the stock, inasmuchas there are no fiat surfaces to produce dead spaces and no sharp edgesto promote stapling. Further, the means disclosed herein for removingthe fastest moving 10% to 30% of the stock from the stream of stock enroute to the slice facilities the provision of a substantially uniformstock velocity across the slice and permits independent adjustments ofthe rate of delivery of stock to the flow system and the rate ofdelivery of stock by the flow system to the paper-forming machine.

Thus, there is provided in accordance with the invention a novel andhighly-effective paper-stock-flow system adapted to provide a flow ofdeflocculated stock to a slice of uniform velocity across the slice andto operate substantially free of hang-up.

Many modifications in form and detail of the representative embodimentsof the invention disclosed herein will readily occur to those skilled inthe art. For example, the peripheral stock-contacting surfaces of thespools need not be generated by a semicircle and need not in fact besurfaces of revolution or symmetrical with respect to a plane parallelto and equidistant from the walls 122 and 123. It is sufiicient that theintersections of each surface with all planes containing the axis of thespool to which such surface is proper be generally concave outward.Accordingly, the invention is to be construed as including all of themodifications which fall within the scope of the appended claims.

I claim:

1. In a paper-stock-fiow system for delivering a paper stock to apaper-forming machine, first and second opposed walls facilitatingformation of a flow channel therebetween and stock-deflocculation meansmounted in said flow channel, said stock-deflocculation means having anaxis extending between said walls and a peripheral surface in contactwith said stock, the intersections of said peripheral surface with allplanes containing said axis being generally concave outward.

2. In a paper-stock-fiow system for delivering a paper stock to apaper-forming machine, first and second opposed walls generally parallelto each other and separated from each other a distance d,stock-flow-channeling means mounted between and connected to said walls,and

means for establishing a flow of stock in a given direction past saidstock-flow-channeling means, said stock-flowchanneling means having (I)an axis of length equal to d normal to said walls and extendingtherebetween, and

(II) a peripheral surface of partial revolution generated by asemicircle, said semicircle (A) having a center a distance x from saidfirst wall and R from said axis. (B) being a line of partial revolutiongenerated by a point, said point being (1) located a distance r fromsaid center and (2) revolved about said center through an arc of saidare lying (a) between said axis and a limiting diametric chord of saidsemicircle parallel to said axis and (b) in the plane of said chord andaxis,

and (C) being revolved about said axis through an arc of substantially180 which (1) is angularly limited by a plane substantially normal tosaid direction of flow and (2) lies upstream of said plane.

3. In a paper-stock-flow system for delivering a paper stock to apaper-forming machine, first and second opposed walls generally parallelto each other and separated from each other a distance d, a plurality ofstockfiow-channeling means mounted between and connected to said walls,and means for establishing a flow of stock in a given direction pastsaid stock-fiow-channeling means, each of said stock-flow-channelingmeans having (I) an axis of length equal to d normal to said walls andextending therebetween and (II) a peripheral surface of partialrevolution generated by a semicircle, said semicircle (A) having acenter a distance x from said first wall and R from said axis, (B) beinga line of partial revolution generated by a point, said point being 1)located a distance r from said center and (2) revolved about said centerthrough an arc of 180, said are being (a) between said axis and alimiting diametric chord of said semicircle parallel to said axis and(b) in the plane of said chord and axis,

and (C) being revolved about said axis through an arc of substantially180 which (1) is angularly limited by a plane substantially normal tosaid direction of flow and (2) lies upstream of said plane andsuccessive ones of said stock-flow-channeling means being substantiallytangent to each other to define a flow channel for said stock ofsubstantially circular cross section in said plane.

4. Apparatus as defined in claim 3 further comprising tube meanscommunicating with said flow channel and extending away therefrom insaid direction of flow, said tube means having a cross sectioncomplemental in shape to said flow channel.

5. In a paper-stock-fiow system for delivering a paper stock to apaper-forming machine, first and second opposed walls facilitatingformation of a flow channel therebetween, means for establishing a flowof paper stock in said system, various parts of said stock at a givenlocation in said system moving at different speeds, stock-deflecculationmeans mounted in said flow channel, said stockdeflocculation meanshaving an axis extending between said walls and a peripheral surface incontact with said stock, the intersections of said peripheral surfacewith all planes containing said axis being generally concave outward,and stock-withdrawal means at said location 9 10 for withdrawing fromsaid flow a portion of said stock of delivery of said stock by said flowsystem to said to reduce the standard deviation of the speeds of thepaper-forming machine. parts of said stock remaining in said fiowsystem.

6. In a paper-stock-flow system for delivering a paper References Citedstock to a paper-forming machine, a channel for estab- 5 UNITED STATESPA lishing a flow of paper stock in said system, said system includingstock-withdrawal means for withdrawing from said flow a proportion ofsaid stock, said means being variable to permit independent adjustmentsof the rate of DONALL SYLVESTER Primary Exammer' delivery of said stockto said flow system and the rate 10 HODGSON, ASSl-Ymm Examiner-3,098,787 7/1963 Sieber 162343

